title: Dye-coupled electrode system for the rapid determination of cell populations in polluted water.
abstract: We determined cell populations in polluted waters by using a fuel cell-type electrode. The electrode was constructed from a platinum anode, a silver peroxide cathode, and a membrane filter for retaining microorganisms. The principle of cell number determination is based on sensing a redox dye reduced by the microorganisms with the electrode. Sample solutions containing microorganisms were membrane filtered, and the resulting filter containing microbial cells was attached to the surface of a platinum anode. The electrode was immersed in phosphate buffer solution (0.05 M, pH 7) containing a redox dye (2,4-dichlorophenol-indophenol), and the current generated was measured. The response time of the electrode system was 10 to 20 min, and the current generated was proportional to cell populations above 10(4) cells/ml.
mesh_terms: D001412:Bacillus subtilis / Q000302:isolation & purification; D004396:Coloring Agents; D004566:Electrodes; D004926:Escherichia coli / Q000302:isolation & purification; D005374:Filtration / Q000379:methods; D005417:Flavobacterium / Q000302:isolation & purification; D008722:Methods; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D014871:Water Microbiology
chemical_list: D004396:Coloring Agents